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Abstract:

A modularized respiratory treatment apparatus provides various
respiratory pressure treatments. The apparatus may be formed by discrete
connectable modules such as a flow generator module, alarm module and/or
humidifier module. Each module may include its own external casing or
housing to independently retain or enclose the respective components that
serve the function of the module. Different modules may be adapted with
different components and functionalities and may be readily coupled using
standardized gas and electrical connection configurations that have flow
and communication paths that extend through the modules. When coupled,
operation of the respiratory treatment apparatus may be controlled by
detection of different modules, such as the alarm module that generates
visual and/or audible alarms based on detected conditions, so as to
selectively enable or disable different respiratory treatments. The
discrete modules of the medical treatment apparatus may include tamper
resistant locking mechanisms to impede unauthorized separation of some
modules.

Claims:

1. An alarm module for coupling with a respiratory treatment apparatus,
the respiratory treatment apparatus being configured to generate a
respiratory pressure treatment, the alarm module comprising: a breathable
gas flow channel, the channel comprising an inlet coupling and outlet
coupling, the inlet coupling adapted to couple with a breathable gas flow
output of the respiratory treatment apparatus; an alarm component; an
electrical coupler, the coupler adapted for electrical communication
between the alarm component and a controller of the respiratory treatment
apparatus; and a modularized housing configured to retain the channel and
the alarm component, the modularized housing adapted for removable
coupling with a housing of the respiratory treatment apparatus.

2. The alarm module of claim 1 further comprising an alarm controller
including at least one processor, the processor configured for activating
an alarm associated with operation of the respiratory treatment
apparatus, wherein the controller is retained by the modularized housing.

3. The alarm module of claim 2 further comprising a speaker, wherein the
alarm controller is coupled to the speaker and adapted to produce the
alarm as an audible sound, and wherein the speaker is retained by the
modularized housing.

4. The alarm module of claim 2 further comprising a set of lights,
wherein the alarm controller is coupled to the set of lights and
configured to produce the alarm as a visual warning, and wherein the set
of lights is retained by the modularized housing.

5. The alarm module of claim 2 further comprising a pressure sensor to
sense a pressure of the breathable gas of the channel, wherein the alarm
controller is coupled to the sensor and configured to produce the alarm
based on a signal of the pressure sensor, and wherein the pressure sensor
is retained by the modularized housing.

6. The alarm module of claim 2 further comprising a microphone to sense
ambient noise, wherein the alarm controller is coupled to the microphone
and configured to produce the alarm based on a signal of the microphone,
and wherein the microphone is retained by the modularized housing.

7. The alarm module of claim 2 wherein the modularized housing comprises
a locking mechanism for releasably locking the modularized housing in a
coupling arrangement with the housing of the respiratory treatment
apparatus.

8. The alarm module of claim 7 wherein the locking mechanism comprises a
set of latches.

9. The alarm module of claim 8 further comprising a spring, wherein the
set of latches is coupled with the spring.

10. The alarm module of claim 9 wherein the modularized housing comprises
an access aperture for releasing the set of latches.

11. The alarm module of claim 10 wherein the locking mechanism further
comprises a securing screw, the securing screw comprising first and
second thread sections, the second thread sections configured for
threaded attachment to a screw hole of the set of latches for retaining
the locking mechanism in a locked arrangement.

12. The alarm module of claim 11 wherein the securing screw comprises an
unthreaded shaft portion between the first and second threaded sections,
the unthreaded shaft portion being configured to slideably traverse
within the screw hole of the set of latches for releasing the locking
mechanism from a locked arrangement.

13. The alarm module of claim 2 further comprising: a further electrical
coupler, the further coupler adapted for electrical communication between
the controller of the respiratory treatment apparatus and a controller of
a humidifier module for the respiratory treatment apparatus; and a
further locking mechanism for releasably locking the modularized housing
in a coupling arrangement with a housing of a modularized humidification
module for the respiratory treatment apparatus, wherein the outlet
coupling of the alarm module is adapted for engagement with a breathable
gas input to the humidification module.

14. The alarm module of claim 13 wherein the further locking mechanism
comprises a set of apertures of the modularized housing configured to
releasably engage with a set of latches of a housing of the modularized
humidification module.

15. A system for respiratory pressure treatment, the system comprising: a
respiratory pressure treatment module having a flow generator, the
respiratory pressure treatment module including a controller, with at
least one processor, the controller configured to control the flow
generator to generate a pressure treatment to a patient interface
according to first and second pressure therapy regimes, wherein the
controller is configured to enable the first pressure therapy regime and
disable the second pressure therapy regime in an absence of a detection
by the controller of an alarms module.

16. The system of claim 15 wherein the controller of the respiratory
pressure treatment module is configured to enable the second pressure
therapy regime based on a detection by the controller of a presence of
the alarms module.

17. The system of claim 16 further comprising the alarms module, the
alarms module including: a breathable gas flow channel including an inlet
coupling and outlet coupling, the inlet coupling adapted to couple with a
breathable gas flow output of the respiratory pressure treatment module;
an alarm controller including at least one processor, the processor
configured for activating an alarm associated with operation of the
respiratory pressure treatment module; an electrical coupler, the coupler
adapted for electrical communication between the alarm controller and the
controller of the respiratory pressure treatment module; and a
modularized housing configured to retain the channel and the alarm
controller, the modularized housing adapted for removable coupling with a
housing of the respiratory pressure treatment module.

18. The system of claim 15 wherein the first pressure therapy regime
comprises a continuous positive airway pressure treatment.

19. The system of claim 15 wherein the second pressure therapy regime
comprises a pressure support ventilation.

20. A method for selectively activating a pressure therapy regime in a
pressure treatment apparatus comprising: in a processor of a flow
generator module of a pressure treatment apparatus, detecting a presence
or absence of a coupled alarms module, the alarms module being adapted
for releasable coupling with the flow generator module; and with the
processor of the flow generator module, selecting a pressure therapy
regime from a plurality of distinct pressure therapy regimes based on the
detection of a presence or absence of the alarms module.

21. The method of claim 20 further comprising, with the processor of the
flow generator, controlling a generation of a flow of breathable gas
according to the selected pressure therapy regime.

22. The method of claim 20 wherein a first pressure therapy regime of the
plurality of distinct pressure therapy regimes comprises a CPAP
treatment.

23. The method of claim 22 wherein the first pressure therapy regime is
selected with processor in the absence of the detection of the alarms
module.

24. The method of claim 23 wherein a second pressure therapy regime is
disabled with processor in the absence of the detection of the alarms
module.

25. The method of claim 22 wherein a second pressure therapy regime of
the plurality of distinct pressure therapy regimes comprises bi-level
pressure support ventilation.

26. The method of claim 25 wherein the second pressure therapy regime is
selected with the processor in the presence of the detection of the
alarms module.

27. A tamper resistant locking mechanism for releasably coupling discrete
modules of a treatment apparatus, the locking mechanism comprising: a
movable latching portion, the movable latching portion being adapted for
engagement with engagement apertures of a first housing structure; and a
securing shaft configured to secure the latching portion, the securing
shaft comprising first and second sets of threads and an unthreaded shaft
portion, the first and second sets of threads being separated by the
unthreaded shaft portion.

28. The locking mechanism of claim 27 wherein the latching portion
comprises a threaded aperture for the securing shaft, the latching
portion adapted to be secured against a second housing structure by
coupling the second set of threads and threaded aperture so as to prevent
displacement of the latching portion from the engagement apertures.

29. The locking mechanism of claim 28 wherein the threaded aperture of
the latching portion is adapted for slideable engagement with the
unthreaded portion of the securing shaft to permit the latching portion
to be moved for releasing and catching the latching portion.

30. The locking mechanism of claim 28 wherein the second housing
structure comprises a release aperture, the release aperture positioned
and sized to selectively permit access to the latching portion to
displace the latching portion for releasing the latching portion from the
engagement apertures.

31. The locking mechanism of claim 28 wherein the second housing
structure comprises an shaft aperture for receiving the securing shaft
and engaging the securing shaft when the latching portion is secured
against the second housing structure with the second set of threads of
the securing shaft.

32. The locking mechanism of claim 31 further comprising a security label
to conceal the shaft aperture.

34. The locking mechanism of claim 28 wherein the first housing structure
comprises a housing to retain a flow generator of a respiratory treatment
apparatus and wherein the second housing structure comprises a housing to
retain an alarms module for the respiratory treatment apparatus.

Description:

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of the filing date of U.S.
Provisional Patent Application No. 61/533,431 filed Sep. 12, 2011, the
disclosure of which is hereby incorporated herein by reference.

[0003] Sleep is important for good health. Frequent disturbances during
sleep or sleep fragmentation can have severe consequences including
day-time sleepiness (with the attendant possibility of motor-vehicle
accidents), poor mentation, memory problems, depression and hypertension.
For example, a person with nasal congestion may snore to a point that it
disturbs that person's ability to sleep. Similarly, people with OSA are
also likely to disturb their partner's sleep. One form of treatment for
patients with OSA is continuous positive airway pressure (CPAP) applied
by a flow generator such as a blower (compressor) via a connecting
delivery hose with a patient interface. Such a pressure treatment may be
adjusted in response to detected patient conditions such as apneas,
snoring or hypopneas but generally maintains an approximately constant
positive pressure during each breathing cycle of the patient. The
positive pressure can prevent a collapse of the patient's airway during
inspiration, thus preventing events such as snoring, apneas or hypopneas
and their sequelae.

[0004] Respiratory treatment apparatus may include a flow generator, an
air filter, a patient interface such as a mask or cannula, an air
delivery conduit connecting the flow generator to the mask, various
sensors and a microprocessor-based controller. The flow generator may
include a servo-controlled motor and an impeller. The flow generator may
also include a valve capable of discharging air to atmosphere as a means
for altering the pressure delivered to the patient as an alternative to
motor speed control. The sensors may measure, amongst other things, motor
speed, gas volumetric flow rate and outlet pressure, such as with a
pressure transducer, flow sensor or the like. The apparatus may
optionally include a humidifier and/or heater elements in the path of the
air delivery circuit. The controller may include data storage capacity
with or without integrated data retrieval/transfer and display functions.

[0005] Positive airway pressure may be delivered in many forms. As
previously mentioned, a CPAP treatment may maintain a treatment pressure
across the inspiratory and expiratory levels of the patient's breathing
cycle at an approximately constant level. Alternatively, pressure levels
may be adjusted to change synchronously with the patient's breathing
cycle. For example, pressure may be set at one level during inspiration
and another lower level during expiration for patient comfort. Such a
pressure treatment system may be referred to as bi-level. Alternatively,
the pressure levels may be continuously adjusted to smoothly replicate
changes in the patient's breathing cycle. A pressure setting during
expiration lower than inspiration may generally be referred to as
expiratory pressure relief. As described by Sullivan in U.S. Pat. No.
4,944,310, positive airway pressure treatments typically provide gas
under pressures to the patient in the range of 4 to 15 cmH2O from
the device and may involve flow rates of at about 120 liters/minute. Some
of the air may escape via an end restriction and not be delivered to the
patient. These pressure settings may also be adjusted based on the
detection of conditions of the patient's airway or respiration. For
example, treatment pressure may be increased in the detection of partial
obstruction, apnea or snoring. In some cases, positive airway pressure
may be adapted to provide ventilation support. For example, a patient's
ventilatory needs may be supported on a breath-by-breath basis by
automatically calculating a target ventilation and adjusting the pressure
support generated by an apparatus, such as a bi-level pressure treatment
apparatus, so as to achieve the target ventilation.

[0006] Other devices are known for providing respiratory tract therapy.
For example, Schroeder et al. describes an apparatus for delivering
heated and humidified air to the respiratory tract of a human patient in
U.S. Pat. No. 7,314,046, which was filed on 8 Dec. 2000 and assigned to
Vapotherm Inc. Similarly, Genger et al. discloses an anti-snoring device
with a compressor and a nasal air cannula in U.S. Pat. No. 7,080,645,
filed 21 Jul. 2003 and assigned to Seleon GmbH.

[0007] Respiratory treatment apparatus are sometimes provided with
accessory components for comfort conditioning of the flow or pressurized
air supplied by the flow generator. For example, the supplied air may be
applied to a humidifier to humidify and warm the treatment gas prior to
its delivery to a patient. Similarly, various heating elements can be
connected with a delivery conduit to help in maintaining a particular
temperature of the supplied gas as it is conducted to the patient from a
supply unit or humidifier.

[0008] It may be desirable to develop these devices with improved design
efficiencies.

SUMMARY OF THE TECHNOLOGY

[0009] In an aspect of the present technology, apparatus and methods
provide respiratory treatment for a patient.

[0010] In another aspect of the present technology, a respiratory
treatment apparatus is formed by separable modules each with its own
external casing or housing.

[0011] Another aspect of one form of the present technology is a system
comprising a first module that is constructed and arranged to provide
Positive Airway Pressure (PAP) therapy, and a second module that is
constructed and arranged to provide mitigation in the event of an alarm
condition being fulfilled with respect to the therapy in use. In one
form, the two modules may be physically connected. In one form, the
second module may be in data communication with the first module, without
being physically connected, and nevertheless provide alarm functionality.

[0012] Another aspect of the present technology is a tamper resistant
respiratory apparatus.

[0013] In another aspect of the technology, a respiratory treatment
apparatus includes a separable alarm module, a separable flow generator
module and a separable humidifier module. Such a separable design may be,
from the perspective of the ordinary user, a permanent attachment or at
least an attachment that is difficult for such a user to detach. However,
it may be readily separable by a trained technician for service or
replacement. Nevertheless, the design can provide a very easy to attach
module that simplifies upgrading of a flow generator or other respiratory
apparatus so as to add an additional functionality, such as an alarm
functionality.

[0014] Another aspect of the present technology is a system comprising
respiratory treatment apparatus and a module that is connectable to and
removable from the respiratory treatment apparatus via a latching
mechanism, wherein the latching mechanism has an associated connection
step and a removing step that is not a reversal of the connection step.
Another aspect of the present technology is a process of assembly of a
module to a respiratory apparatus, and a process of removal of the module
from the respiratory apparatus. In one form, the process of removal of
the module comprises additional or alternative steps to the process of
assembly of the module.

[0015] In some embodiments, the technology involves an alarm module for
coupling with a respiratory treatment apparatus. The respiratory
treatment apparatus may be configured to generate a respiratory pressure
treatment. The alarm module may include a breathable gas flow channel.
The channel may include an inlet coupling and outlet coupling such that
the inlet coupling is adapted to couple with a breathable gas flow output
of a respiratory treatment apparatus. The alarm module may also include
an alarm component. The module may further include an electrical coupler
that is adapted for electrical communication between the alarm component
and a controller of the respiratory treatment apparatus. The alarm module
may also include a modularized housing configured to retain the channel
and the alarm component. The modularized housing may be adapted for
removable coupling with a housing of the respiratory treatment apparatus.

[0016] In some embodiments, the apparatus may also include an alarm
controller including at least one processor. The processor may be
configured for activating an alarm associated with operation of the
respiratory treatment apparatus. The controller may be retained by the
modularized housing. In some cases, the alarm module may include a
speaker, wherein the alarm controller is coupled to the speaker and
adapted to produce the alarm as an audible sound, and wherein the speaker
is retained by the modularized housing. The alarm module may also include
a set of lights, wherein the alarm controller is coupled to the set of
lights and configured to produce the alarm as a visual warning, and
wherein the set of lights is retained by the modularized housing.

[0017] One aspect of one form of the present technology is the use of a
loudspeaker as an alarm output device.

[0018] Another aspect of one form of the present technology is a high
efficiency audio driver, preferably a switching mode audio driver,
preferably a class D audio amplifier, which may drive the speaker.

[0019] Another aspect of one form of the present technology is an
electrical sub-system that uses frequency synthesizing to achieve an
alarm spectrum.

[0020] In some cases, the alarm module may also include a pressure sensor
to sense a pressure of the breathable gas of the channel, wherein the
alarm controller is coupled to the sensor and configured to produce the
alarm based on a signal of the pressure sensor, and wherein the pressure
sensor is retained by the modularized housing. The alarm module may also
include a microphone to sense ambient noise, wherein the alarm controller
is coupled to the microphone and configured to produce the alarm based on
a signal of the microphone, and wherein the microphone is retained by the
modularized housing.

[0021] Optionally, the modularized housing may include a locking mechanism
for releasably locking the modularized housing in a coupling arrangement
with the housing of the respiratory treatment apparatus. The locking
mechanism may include a set of latches. The set of latches may be coupled
with a spring. The modularized housing may also include an access
aperture for releasing the set of latches. The locking mechanism may also
include a securing screw, the securing screw comprising first and second
thread sections, the second thread sections configured for threaded
attachment to a screw hole of the set of latches for retaining the
locking mechanism in a locked arrangement. Optionally, the securing screw
may include an unthreaded shaft portion between the first and second
threaded sections, the unthreaded shaft portion being configured to
slideably traverse within the screw hole of the set of latches for
releasing the locking mechanism from a locked arrangement. In one form,
the securing screw has a double start thread. In another form, the
securing screw has a three or more start thread.

[0022] In some cases, the alarm module may also include a further
electrical coupler, the further coupler adapted for electrical
communication between the controller of the respiratory treatment
apparatus and a controller of a humidifier module for the respiratory
treatment apparatus. In some such cases, the alarm module may also
include a further locking mechanism for releasably locking the
modularized housing in a coupling arrangement with a housing of a
modularized humidification module for the respiratory treatment
apparatus. Optionally, the outlet coupling of the alarm module may be
adapted for engagement with a breathable gas input to the humidification
module. The further locking mechanism may comprise a set of apertures of
the modularized housing configured to releasably engage with a set of
latches of a housing of the modularized humidification module.

[0023] Some embodiments of the present technology may involve a system for
respiratory pressure treatment. The system may include a respiratory
pressure treatment module having a flow generator, the respiratory
pressure treatment module including a controller, with at least one
processor, the controller configured to control the flow generator to
generate a pressure treatment to a patient interface according to first
and second pressure therapy regimes, wherein the controller is configured
to enable the first pressure therapy regime and disable the second
pressure therapy regime in the absence of a detection by the controller
of an alarms module. In some cases, the controller of the respiratory
pressure treatment module may be configured to enable the second pressure
therapy regime based on a detection by the controller of a presence of
the alarms module.

[0024] Optionally, the alarms module of the system may include a
breathable gas flow channel including an inlet coupling and outlet
coupling, the inlet coupling adapted to couple with a breathable gas flow
output of the respiratory pressure treatment module. It may also include
an alarm controller having at least one processor, the processor
configured for activating an alarm associated with operation of the
respiratory pressure treatment module. The module may also have an
electrical coupler, the coupler adapted for electrical communication
between the alarm controller and a controller of the respiratory
treatment apparatus; and a modularized housing configured to retain the
channel and the alarm controller, the modularized housing adapted for
removable coupling with a housing of the respiratory pressure treatment
module.

[0025] In some cases, the first pressure therapy regime may include a
continuous positive airway pressure treatment. The second pressure
therapy regime may include a pressure support ventilation.

[0026] Some embodiments of the present technology may involve a method for
selectively activating a pressure therapy regime in a pressure treatment
apparatus. The method may be executed by a processor of a flow generator
module of a pressure treatment apparatus. The method may involve
detecting a presence or absence of a coupled alarms module, the alarms
module being adapted for releasable coupling with the flow generator
module. The method may also involve selecting a pressure therapy regime
from a plurality of distinct pressure therapy regimes based on the
detection of a presence or absence of the alarms module. The method may
also involve controlling a generation of a flow of breathable gas
according to the selected pressure therapy regime. In some cases, a first
pressure therapy regime of the plurality of distinct pressure therapy
regimes may involve a CPAP treatment. The first pressure therapy regime
may be selected with processor in the absence of the detection of the
alarms module. In some such cases, a second pressure therapy regime may
be disabled by the processor in the absence of the detection of the
alarms module. Optionally, a second pressure therapy regime of the
plurality of distinct pressure therapy regimes comprises bi-level
pressure support ventilation. Optionally, the second pressure therapy
regime may be selected with the processor in the presence of the
detection of the alarms module.

[0027] Another embodiment of the present technology may involve a tamper
resistant locking mechanism for releasably coupling discrete modules of a
treatment apparatus. The locking mechanism may include a movable latching
portion, the movable latching portion being adapted for engagement with
engagement apertures of a first housing structure. It may also include a
securing shaft configured to secure the latching portion, the securing
shaft comprising first and second sets of threads and an unthreaded shaft
portion, the first and second sets of threads being separated by the
unthreaded shaft portion.

[0028] In some such cases, the latching portion may include a threaded
aperture for the securing shaft. The latching portion may be adapted to
be secured against a second housing structure by coupling the second set
of threads and threaded aperture so as to prevent displacement of the
latching portion from the engagement apertures. Optionally, the threaded
aperture of the latching portion may be adapted for slideable engagement
with the unthreaded portion of the securing shaft to permit the latching
portion to be moved for releasing and catching the latching portion. In
some cases, the second housing structure may include a release aperture,
the release aperture positioned and sized to selectively permit access to
the latching portion to displace the latching portion for releasing the
latching portion from the engagement apertures.

[0029] Optionally, the second housing structure may include a shaft
aperture for receiving the securing shaft and engaging the securing shaft
when the latching portion is secured against the second housing structure
with the second set of threads of the securing shaft. The locking
mechanism may also include a security label to conceal the shaft
aperture. In some cases, the securing shaft may comprise a screw. Also,
the first housing structure may include a housing to retain a flow
generator of a respiratory treatment apparatus and wherein the second
housing structure comprises a housing to retain an alarms module for the
respiratory treatment apparatus.

[0030] Further embodiments and features of the present technology will be
apparent from the following detailed disclosure, abstract, drawings and
the claims.

BRIEF DESCRIPTION OF DRAWINGS

[0031] The present technology is illustrated by way of example, and not by
way of limitation, in the figures of the accompanying drawings, in which
like reference numerals refer to similar elements including:

[0032]FIG. 1 is a schematic diagram of example modules with components of
an apparatus for respiratory treatment in some embodiments of the present
technology;

[0033]FIG. 2 illustrates an embodiment of a modularized respiratory
treatment apparatus having a flow generator module, alarm module and
humidifier module in a side-by-side coupled arrangement;

[0034]FIG. 3 illustrates another embodiment of the modularized
respiratory treatment apparatus having a flow generator module and
humidifier module in a side-by-side coupled arrangement;

[0035]FIG. 4 illustrates another embodiment of the modularized
respiratory treatment apparatus having a flow generator module and alarm
module in a side-by-side coupled arrangement;

[0036]FIG. 5 illustrates another embodiment of the modularized
respiratory treatment apparatus having only a flow generator module;

[0037] FIGS. 6A and 6B contain left and right side views that illustrate
an embodiment of a modularized alarm module of the present technology;

[0038]FIG. 7 is an electronic components schematic of an example
arrangement of components of the modularized flow generator, alarm module
and humidifier module in some embodiments of the present technology;

[0039] FIGS. 8A and 8B are left and right side isometric projections of an
example embodiment of the modularized alarm module of the present
technology;

[0040]FIG. 9 is an isometric projection having an exploded view of
example components of the assembly of the modularized alarm module of
FIG. 8;

[0041]FIG. 10 is a three dimensional drawing of some components of a
locking mechanism for a module of a respiratory treatment apparatus of
the present technology;

[0042] FIG. 10A is another view of the components of the locking mechanism
of FIG. 10;

[0043] FIG. 11 is a cross sectional view of a latching structure of an
example locking mechanism of the present technology showing the locking
mechanism in secured and engaged position;

[0044]FIG. 12 is a cross sectional view of the latching structure of the
locking mechanism of FIG. 11 showing the locking mechanism in unsecured,
biased and engaged position;

[0045] FIG. 13 is a cross sectional view of the latching structure of the
locking mechanism of FIG. 11 showing the locking mechanism in a
disengaged position; and

[0046]FIG. 14 is a cross sectional view of the latching structure of the
locking mechanism of FIG. 11 showing the locking mechanism in a engaged
position.

DETAILED DESCRIPTION

[0047] Embodiments of the present technology may be useful for
implementation as a respiratory treatment apparatus 102 that may be
formed by some or all of the modules illustrated in FIGS. 1 to 6. For
example, the respiratory treatment apparatus 102 may be formed by a
system of modules, each with housings that independently retain the
respective components that serve the function(s) of the individual
modules. Desirably, each module may be adapted with different components
and functionalities and may be easily coupled together depending on the
desired functionality of the respiratory treatment apparatus. Thus, when
so coupled, the operation of the respiratory treatment apparatus 102 may
be dictated based on the presence or absence of the different modules
that may be detected. The modules may be coupled in a horizontal or
side-by-side assembly as illustrated in FIGS. 2-4. However, other
assembly orientations may be adapted. For example, a vertical or stacking
of modules may also be adopted.

[0048] In one form of the present technology, a first printed circuit
board (PCB) is constructed to provide therapy functionality, for example
a pressure controller, under the control of a controller that is
programmed to control delivery of one or more therapeutic regimes.
Furthermore, a second, separate PCB is manufactured that is constructed
and arranged to provide mitigation actions, for example the signaling of
an alarm condition in the event of a low power situation. In use, while a
module including only the first PCB has the capability of providing
certain therapies, the module will not do so, or will only permit a
subset of such therapies, unless a second module containing the second
PCB is in data communication with the first module. The data
communication may be wireless, but preferably wired.

[0049] As illustrated in the example of FIG. 1, the respiratory treatment
apparatus may include a system formed by one or more of a flow generator
module 104, an alarm module 106 and/or a humidifier module 108. Each
module includes the components for its modularized functionality.
Depending on the presence or absence of the alarm module and/or
humidifier module, the flow generator may operate differently.

[0050] For example, an alarm module may generally include components and
functionality for generating different types of alarms associated with
the operations of the flow generator as discussed in more detail herein.
The presence of an alarm module, or particular type of alarm module, can
then permit the flow generator to deliver different treatments depending
on its participation in the operation of the apparatus. For example, in
some embodiments, without coupling with an alarm module, the flow
generator may be enabled for certain pressure treatment regimes, such as
a CPAP treatment, and not others, such as a pressure support ventilation
treatment, even though the control programming for each of these
different pressure treatment regimes is present in the flow generator
module. In such a case, certain pressure treatment regimes may be
disabled in the absence of any necessary module such as the alarm module.
However, when a particular module, such as an alarms module, is coupled
to the system, the flow generator may then be enabled to operate with the
further pressure treatment regimes.

[0051] For example, by detecting the alarm module, different pressure
treatment regimes that may be associated with a need for the alarm module
may be activated by a controller of the flow generator. Such a detection
and activation may be fully automated in conjunction with the controllers
of the flow generator module and alarms module. Alternatively, it may be
partially automated such as by permitting an authorized person to select
and activate a pressure treatment regime when the added module has been
detected by a controller of the flow generator. Similarly, removing of
such an alarm module may then disable any pressure therapy regime of the
flow generator that may be associated with the removed module. Thus, the
flow generator may include programming that serves a safety function to
permit enabling or disabling of different pressure treatment regimes
depending on the need for certain functionality of other modules in the
control of the particular pressure treatment regime.

[0052] Accordingly, in some embodiments, the flow generator module may
typically include a flow generator housing 104H so as to retain
components that may be involved in the generation of a pressure treatment
according to one or more pressure treatment regimes. Typically such a
module will include a flow generator such as a servo-controlled blower
with an air inlet and impeller driven by a motor and a programmable
controller for controlling the blower. Optionally, the air inlet may be
coupled with a gas supply, such as for oxygen, to mix with or supplement
the breathable gas supplied by the impeller to the airway of a user.
Moreover, an air filter may be provided, such as a HEPA filter, to remove
dust or other allergens from the air drawn into the air inlet. The flow
generator may optionally be configured for generating pressure treatment
depending on the enabled type of pressure treatment regime (e.g.,
continuous level, bi-level, varying level, pressure support etc.) and it
may further be adjusted based on respiratory conditions (e.g., central or
obstructive apnea, hypopnea, Cheyne-Stokes breathing, inadequate
ventilation, etc.) that may be detected by the apparatus. Optionally such
a module may also include a pressure sensor and/or flow sensor for
controlling the blower and/or detecting conditions associated with
patient's use of the device.

[0053] The controller or processor of the flow generator module 104 is
typically configured and adapted to implement the control methodologies
such as the methods and algorithms described herein. Thus, the controller
may include integrated chips, a memory and/or processor control
instructions or data in an information storage medium. For example,
programmed instructions encompassing the control methodology may be coded
on integrated chips in the circuits or memory of the device or such
instructions may be loaded as software or firmware using an appropriate
medium. With such a controller or processor, the apparatus can configured
with the different pressure treatment regimes by including different
pressure delivery equations that are used to set the speed or pressure of
the blower or the exhaust venting by the release valve. The controller
may enable or disable some treatment regimes based on the detection of
the presence of some module (e.g., an alarm module) that may be required
for the particular pressure treatment regime. Similarly, it may enable or
disable some treatment regimes based on the absence of some module. In
one form, the controller may be configured to control disabling of all
treatment functionality if an alarm module is connected (e.g., it was
detected previously or in a previous session) and then removed (e.g., it
is not subsequently again detected). This control feature may thus
disable functionality that may have been available and operable prior to
the detection of the connection of the alarm module.

[0054] The flow generator module 104 may also typically be adapted to
couple with a patient interface such as a flow delivery conduit and a
mask or nasal prongs or nasal cannula, etc. to carry a flow of air or
breathable gas to a patient's airway. In this way it may deliver a
pressure treatment generated by the flow generator.

[0055] The flow generator module may couple with the patient interface
either directly or through one or more other modules. To this end, the
flow generator housing 104H may include a breathable gas output coupling
110FG. The outlet or output coupling may be adapted for connection to the
tubing of a patient interface or an inlet or input coupling of another
module, such as an input gas coupling 112AM of the alarm module or the
input gas coupling 112HM of a humidifier housing 108H of humidifier
module 108. Similarly, each module may have an outlet or output
breathable gas coupling such as breathable gas output coupling 110AM of
the alarm module and output coupling 110HM of the humidifier module. In
this way, a breathable gas channel (illustrated in FIG. 1 as line "GC")
from the flow generator may be formed by and extend through one or more
modules to the patient interface from the flow generator module.

[0056] Optionally, a module of the system, such as the flow generator
module may couple to a further sensor module such as a pulse oximeter
module. For example, the pulse oximeter module may have a housing that
attaches to the housing of the flow generator module. The pulse oximeter
may optionally measure blood gas, such as with a finger sensor. The pulse
oximeter module then may be configured to communicate information with
the flow generator module, such as detected blood gas data or other
conditions associated with a pulse oximeter.

[0057] Accordingly, the modules of the system may also have one or more
electrical coupler(s) 114 for coupling the modules together for
distributing power, such as from a shared power supply, and/or for
communications between the modules of the system. Thus, the coupler may
include one or more wires to a bus such as the bus described in U.S.
patent application Ser. No. 13/060,566 and PCT/AU2009/001168, the entire
disclosures of which are incorporated herein by reference. In such
embodiments, the modules may each have a signal interface for a processor
of the module for receiving and transmitting signals on the bus.

[0058] Thus, as illustrated in FIG. 1, a module, such as the alarm module,
may have multiple couplers to permit a common bus to be expanded through
one or more modules. In this regard, communication signals from or to an
outer module, such as the humidifier, may pass through other modules,
such as the alarm module, to permit communication with a base module,
such as the flow generator. For example in some embodiments of such a
system, the flow generator module may communicate through the alarm
module to the humidifier module. Optionally, in some embodiments of such
a system, the flow generator module may communicate through the
humidifier module to the alarm module. Communications through additional
modules may also be implemented.

[0059] The structure of each module's housing can provide a basis for
standardizing an attachment configuration for self-alignment of the
electrical and gas flow connections of the modules. In this regard, the
connections may be structured as a portion of each housing, and may do so
without flexible hoses or cables, to permit a simplified attachment of
each connection. For example, with such self-aligning connections, by
aligning the housings of two modules for connection, this may also serve
to align the couplings and couplers for attachment. Thus, when the
housings are aligned for connection, the flow couplings and the
electrical couplers are thereby aligned so as to permit them both to be
connected to their respective ports on each module simply by pushing the
modules together. In such a case, it would not be necessary to separately
connect the gas channel couplings and the electrical couplers. By keeping
such a uniform connection structure (e.g., the distances between the gas
connections and the electrical connections, their size and positioning on
the housing) across different types of modules, it can simplify the use
of different types of modules with a base module that may be the flow
generator.

[0060] In this regard, and as illustrated in FIG. 1, the distance between
the input connections (e.g., the gas connection and the electrical
connection) as well as their size and positioning on both the alarm
module and the humidifier module may be the same for each module to
permit either to be connected directly to the flow generator when it is
serving as the base module. Similarly, the distance between the output
connections (e.g., the gas connection and the electrical connections) as
well as their size and positioning on both the alarm module and the flow
generator module may be the same for each module to permit the
connections. Such a complementary structural design between the different
modules can more easily permit the implementation of a standard flow
generator module that can optionally serve with different additional
modules to become different types of respiratory treatment apparatus that
provide different treatments depending on the presence of the modules.

[0061] Optionally, the housing structures of the modules of the system may
also include one or more connection components to serve as a locking
mechanism 116 that retains at least two modules together for operation
when they are connected. For example, some embodiments may employ a set
of one or more latches 116L and keepers 116K as discussed in more detail
herein. The locking mechanism 116 is adapted as a portion of the
structure of the housings of the modules so that when the locking
mechanism 116 of two modules is aligned to engage for retaining the
housings of the modules together, the gas couplings between the modules
and the electrical couplers between the modules will be in the
appropriate coupled position for operation.

[0062] In some cases, these locking mechanism components may be designed
to be releasable so as to allow simple attachment and separation.
However, they may also be designed so as to inhibit separation once they
are attached. For example, they may be designed to prevent or impede
certain users or patients from releasing the locking mechanism and
separating the housings of the modules but permit others, such as
physicians or manufacturing and maintenance personnel, to release and
separate the housings.

Example Alarm Module Embodiment

[0063] An example embodiment of an alarm module of the system may be
further considered in reference to FIGS. 7 through 9. As schematically
shown in FIG. 7, the alarm module may include several components that
assist with generating alarm signals associated with the operation of a
flow generator to which the module may be attached. As shown, the alarm
module may include visual indicators, such as an LED or LCD, for
conveying status or warning information to a user. For example, the
module may optionally have an alarm display 769, such as an LCD, to
present text warning messages to a user to describe a detected alarm
condition and/or how to resolve or address the alarm condition.
Similarly, and by way of further example, the module may also or
alternatively have status lights 770 and warning lights 772. The status
light may provide an indication that the alarm module is operating and
functioning properly. The warning lights 772 may include a light to
indicate that a treatment therapy is active or not active. The warning
lights may further include an alarm light to indicate that a low and/or
medium priority alarm has been triggered or not. The warning lights may
also include an alarm light to indicate that a high priority alarm has
been triggered or not. Optionally, to audibly convey a warning, the
module may also include an audible indicator such as a loudspeaker 774.

[0064] One or more sensors 776 may also be provided in the alarm module
for detecting a condition associated with a provided treatment. For
example, the sensors may include a pressure sensor and/or a flow sensor
(e.g., differential pressure sensor) to detect pressure and/or flow
conditions in the gas channel GC of the alarm module. Optionally, a
pressure sensor may be provided to sense ambient pressure or the pressure
outside of the gas channel. Such a sensor may provide an ambient pressure
signal to permit the alarm module or another module to determine or
estimate altitude of the system or alarm module. The estimate of altitude
may then be used in the control of the system, such as the setting of
treatment pressure by the flow generator module. Optionally, such a
sensor may generate a warning if a detected ambient pressure or altitude
is not appropriate for use of the respiratory treatment apparatus.

[0065] Optionally, the sensors of the alarm module may also include a
microphone to sense ambient sound or noise. For example, by sensing
ambient sound or noise in the environment in which the alarm module is
being utilized, the alarm module may be used for a process that sets a
suitable sound level of an alarm. For example, by detecting a higher
amplitude noise level in the environment in an ambient sound testing
procedure with the sound sensor, a processor of the module or another
module may automatically set a higher alarm output volume setting
associated with a speaker of the alarm module. When a quieter environment
is detected, a lower setting may be automatically set in the alarm
module. For example, a selected output level for the alarm speaker may be
selected by the module that is a certain threshold level above the sensed
ambient sound/noise level. Such a volume setting process may be executed
when the alarm module is initially powered for operation, periodically
(e.g., every thirty minutes) during use of the system or in a
just-in-time process that is executed by the module immediately before
activation of an audible alarm but after an alarm condition has been
detected.

[0066] The ambient sound sensor may also be utilized in a speaker/alarm
self-testing process. For example, a processor may control activation of
an audible test alarm sound through a speaker of the alarm, such as when
the alarm module is initially powered. The sound sensor may then detect
whether or not the alarm sounded through the speaker by sensing the alarm
sound with the sound sensor. For example, an alarm tone at a known
frequency may be played through the speaker and the sound sensor would
generate a signal from the ambient noise of the environment including the
sound of the alarm tone, which may be accessed as data by a processor.
The processor may then detect whether or not the known frequency exists
within the data of the signal from the sound sensor and/or whether or not
the amplitude component at the detected frequency is at a suitable level.
The existence of the tone and/or the existence of the tone at a
sufficient magnitude would indicate that the alarm speaker is
functioning. If the tone is not located in the signal by the processor or
if the detected frequency does not have a sufficient magnitude, a warning
may be activated by the alarm device such as a written message or a
warning light. The warning may indicate that the speaker is not operating
or the speaker is not operating loudly enough. Optionally, the self
testing process may be conducted during use of the apparatus in response
to the generation of an alarm condition as a test to ensure the alarm is
sounding. Failure to sense the audible alarm may result in an alternative
warning and/or shutting down the apparatus.

[0067] In some embodiments, a microcontroller 778, such as a processor,
may also be included in the alarm module to control the operation of the
audible indicators, the visual indicators, and/or to receive signals from
the sensors via one or more interfaces 780. The microcontroller 778 may
also be coupled to a bus 782 for the system as previously discussed via a
bus interface 784 for communication with other modules such as sending
messages and receiving messages to the other modules, such as the flow
generator module, concerning status of alarm conditions or status of the
alarm module. Optionally, the microcontroller 778 may monitor power with
a power detector 786 coupled with the bus 782. In the event that power
supplied from the bus, such as from a power source associated with the
flow generator module 104 is not sufficient as detected by the power
detector 786, the components of the module may be supplied with power
from an optional back power source 788 such as one or more rechargeable
batteries or supercapacitors.

[0068] The alarm module may also include a user input interface 790 for
user control associated with the alarms. For example, the user input
interface 790 may include a mute button 792 to silence an audible alarm.
It may also optionally include a reset to reset an alarm. The input
interface may also be implemented to set or configure the conditions
associated with the alarms of the alarm module as discussed in more
detail herein.

Example Alarm Module Control Methodologies

[0069] Generally, the alarm module with and/or without the flow generator
module may be considered an intelligent alarm system. As such, the
controller of the alarm module, either independently or depending on the
additional control of another module, such as the microcontroller 796 of
the flow generator module 104, will execute processing to determine the
presence or absence of an alarm condition associated with the respiratory
treatment apparatus and the priority of the alarm.

[0070] Thus, in some embodiments, the microcontroller 778 of the alarm
module may execute prioritized alarm indications, visible and audible,
and may detect alarm conditions under the control of another
microcontroller of a different module, such as the controller of the flow
generator which acts as a master or main controller. However, the
microcontroller 778 of the alarm module may independently detect the
alarm conditions and activate audio and visual alarms as well as generate
signals to other modules concerning the presence and nature of the alarm.
For example, a power fail condition may be detected and an associated
alarm condition may be initiated by the alarm module microcontroller
independently of other module's controller(s). The detection of such a
condition may result in an audible and visual alarm being generated by
the alarm module 106 and a signal being sent to the controller of other
modules concerning the condition.

[0071] In some cases, the alarms generated by the controller of the alarm
module may involve latching alarm signals that activate the audible
and/or visual alarm indicators. A latching alarm signal is one that
continues to be generated after its triggering event is no longer
detected and may be stopped by a deliberate user action, such as the
pressing of a reset button. However, some alarm signals once activated
may not be easily deactivated. In such a case, some alarms may not be
reset by a user. Moreover, in some embodiments, the processing of the
controller(s) may be configured to permit some of the alarms conditions
to be selectable or modifiable by a user or authorized clinician while
some of the alarm conditions may be fixed so as to prevent disablement.

[0072] Example alarms that may be activated and/or detected with the alarm
module may include a power fail condition, a high pressure or over
pressure condition, a system fault (e.g., an over temperature condition,
a blocked tube of a patient interface or blocked gas channel,
disconnected patient interface or tube thereof, a humidifier lid open, a
high leak or Mask Off condition), a non-vented mask condition, a Low
pressure settable condition, a high pressure settable condition, a low
minute ventilation condition, a apnea condition and/or a sensor failure
condition, etc. Whether detected by the alarm module or controller of
another module, the controller of the alarm module will generate the
audible and/or visual alarms associated with these conditions in the
alarm module with the visual and/or audible indicators of the alarm
module. In the case that the condition is detected by the controller of
another module, the detecting module will transmit a signal on the bus to
the alarm module. When the controller of the alarm module receives the
signal, the controller of the alarm module will then generate the
appropriate audible and/or visual alarms based on the type of alarm
message received on the bus.

[0073] Additional example conditions that may be assessed by one or more
controllers for detecting the above listed alarms may be as follows:

[0074] (1) a power fail condition: no power or insufficient power is
detected while the flow generator is delivering a pressure treatment.

[0075] (2) a high pressure or over pressure condition: a sensed pressure
is greater than a pressure threshold (e.g., 25 or 30 depending on the
detected type of flow generated module attached) for a time period
exceeding a time threshold (e.g., 0.7 seconds).

[0076] (3) an over temperature condition: a temperature detected by a
thermister associated with a controller of any attached module has
exceeded a temperature threshold.

[0077] (4) a blocked tube of a patient interface or blocked gas channel: a
measure of patient flow is below a flow threshold (e.g., 12 liters per
minute) and a measure of pressure is above a pressure threshold (e.g., 10
cmH2O) for a period of time exceeding a time threshold (e.g., in a
range of about 30 to 50 seconds, such as 40 seconds).

[0078] (5) a disconnected patient interface or tube thereof: this
condition may be detected when a measure of pressure is less than a
pressure threshold (e.g., 2 cmH2O) and a measure of blower speed is
above a speed threshold (e.g., 8955 revolutions per minute) for a period
of time exceeding a time threshold (e.g., 1 second).

[0079] (6) a humidifier lid open: the presence of the humidifier module is
detected and a lid sensor is detected as being open or a measure of
pressure is detected below a pressure threshold (e.g., 3.5 cmH2O)
and a measure of flow is detected as being over a flow threshold (e.g.,
120 liters per minute) for a time exceeding a time threshold (e.g., 5
seconds).

[0080] (7) a high leak or Mask Off condition: a measure of leak exceeds a
leak threshold (e.g., 40 liters/minute) for a time period exceeding a
time threshold (e.g., 20 seconds). A controller may deactivate this alarm
when the measure of leak falls below the leak threshold for a period of
time (e.g., 6 seconds.)

[0081] (8) a non-vented mask condition: this condition may be detected
when flow generator is determined to be generating a pressure treatment
for a non-vented mask and a measure of leak falls below a leak threshold
(e.g., -7.5 liters per minute) for a period of time that exceeds a time
threshold (e.g., 10 seconds). A controller may deactivate this alarm when
the measure of leak is above a leak threshold (e.g., 7.5 liters per
minute) for a period of time (e.g., 30 seconds.)

[0082] (9) a Low pressure settable condition: this condition may be
detected when a measure of pressure is less than a pressure treatment
setting by some user-configured amount (e.g., 0 to 10 cmH2O) for a
period of time exceeding a time threshold (e.g., 12 seconds). A
controller may deactivate this alarm when the measure of pressure
satisfies the pressure treatment setting for a period exceeding a time
threshold (e.g., 100 milliseconds).

[0083] (10) a high pressure settable condition: this condition may be
detected when a measure of pressure is higher than a pressure treatment
setting by some user-configured margin (e.g., 0 or 4 to 35 cmH2O)
for a period of time exceeding a time threshold (e.g., 7 seconds). A
controller may deactivate this alarm when the measure of pressure
satisfies the pressure treatment setting for a period exceeding a time
threshold (e.g., 100 milliseconds).

[0084] (11) a low ventilation condition: this condition may be detected
when a measure of ventilation (e.g., a minute ventilation) falls below a
configurable ventilation threshold (e.g., 1 to 20 liters per minute). A
controller may deactivate this alarm when the measure of ventilation
satisfies the ventilation threshold for a period of time exceeding a time
threshold (e.g., 30 seconds).

[0085] (12) an apnea condition: this condition may be detected when there
are no breaths detected within a time period exceeding a configurable
time threshold (e.g., 5 to 45 seconds). A controller may deactivate this
alarm when a number of spontaneous breaths (e.g., 3) are detected in the
time period.

[0086] (13) a sensor failure condition (e.g., pressure transducer): this
condition may be detected if the flow generator module is generating a
pressure treatment (e.g., is in run mode) and if a measure of pressure is
less then a pressure threshold (e.g., 1 cmH2O) for over a period of
time exceeding a time threshold (e.g., 5 seconds). Other alarm conditions
may also be implemented.

[0087] (14) Oximeter Sensor Failure: this condition may be detected if a
flow generator module fails to detect a connection to an oximeter module
when the flow generator treatment mode is configured to use an oximeter.
The detection of the absence of the oximeter may result in activation of
an alarm through the alarm module such as a message on an LCD, a warning
light or LED and/or an audible warning sound via a sound generator (e.g.,
a warning tone or an audible voice message advising a user to connect an
oximeter).

[0088] (15) Oximeter Dislodged Condition: This condition may be detected
if an oximeter module detects that an oximeter finger sensor has fallen
off a patient's finger. For example, a pulse oximeter module may detect
the dislodged sensor and send a message to an alarms module via a flow
generator module. The detection of the dislodged sensor may result in
activation of an alarm of the alarm module such as a message on an LCD, a
warning light or LED and/or an audible warning sound via a sound
generator (e.g., a warning tone or an audible voice message advising a
user to wear the sensor).

[0089] (16) Blood Gas Condition: This condition may be detected if a
measured blood gas, such as a blood gas measured by an oximeter module,
does not meet a threshold. For example, if a low oxygen level is
detected, such as if PaO2 falls below a percentage threshold (e.g.,
85%). The detection of the dislodged sensor may result in activation of
an alarm of the alarm module, such as in response to a communication from
the flow generator module. The alarm activated in the alarm module may be
a message on an LCD, a warning light or LED and/or an audible warning
sound via a sound generator (e.g., a warning tone or an audible voice
message advising a user of a low blood gas condition).

[0090] (17) A Back-up Power Source Warning: This condition may be detected
if the back-up power source of the module does not meet required
performance requirements such as holding sufficient power for back-up
operations. For example, in the case of a supercapacitor, the
microcontroller may generate an early warning signal by detecting a
decrease in the capacitance of the supercapacitor. In such a case, the
microcontroller of the alarms module may monitor the charging and/or
discharging rate of the supercapacitor during main power on/off and
determine the approximate capacitance of the supercapacitors. An alarm
may be generated if the determined capacitance does not meet a
predetermined threshold. Other methods for testing the back-up power may
also be implemented and may depend on the type of back-up source. The
alarm activated in the alarm module may be a message on an LCD, a warning
light or LED and/or an audible warning sound via a sound generator (e.g.,
a warning tone or an audible voice message advising a user to seek
service of the back-up power source.)

[0091] The following Table A identifies whether some of the previously
described alarm conditions have settings (e.g., configurable thresholds
for the conditions and/or whether the alarm conditions may be
enabled/disabled) that may be adjusted or configured by a user and/or
clinician and whether the alarms may be reset once they have been
triggered for an example embodiment.

[0092] One aspect of one form of the present technology is an alarm that
uses frequency synthesizing to achieve the alarm spectrum. One example of
an alarm sound signal is to use a microcontroller to synthesize a complex
frequency signal that contains a fundamental frequency and four harmonic
sound frequencies. A digital to analog converter (DAC) may then be used
to produce the required sound signal. An example methodology for
producing the sound signal is as follows:

[0096] k1 . . . k5 are the amplitude coefficients that
will be used to fine tune the sound pressure level of the harmonics;

[0097] φ1 . . . φ5 are the initial phase shift for
individual frequency components. The defaults of the amplitude
coefficients may be set to 1; the default phase shifts may be set to
0°. These coefficients can be tuned as desired.

[0098] 3. Sample the sound signal S(t) at a rate of SR=32×5F0
for a period of T=1/F0; start from t=0;

[0099] 4. Convert the sampled data, such as to an 8-bit DAC dataset for a
digital to analog converter of the microcontroller of the alarm module:

[0100] In one form of the present technology, an alarm speaker is driven
by a switching mode audio driver, for example, a class D amplifier (PWM
modulated by synthesized signal). An advantage of this approach is that
it is a high efficiency amplifier, for example with an electrical
efficiency of 90% or greater. By way of comparison, a class C linear
amplifier may have an electrical efficiency of less than 50%. This high
efficiency amplifier does not need additional storage capacitor and
provides a very wide output volume adjustment range.

Example Alarm Module Structure

[0101] The modularized housing structure of the alarm module may be
considered in more detail in reference to FIGS. 8A, 8B and 9. In this
embodiment, the components of the alarm module housing 106H include an
upper case 806, a lower case 808 and a housing support 810. The upper
case 806 serves as a panel for the mute button 792 and may also include a
panel which may be for a label for the mute button or may optionally be
for an LCD-type alarm display 769 in some embodiments. The lower case 808
serves as a base for the alarm module and may include a window 812 for
warning lights 772.

[0102] The housing support 810, to which the lower case and upper case of
the housing may be attached, contains an electronics board 914 for the
previously described electronics components of the module (e.g., the
microcontroller, bus, sensors, lights, interface for speaker 816 etc.).
For example, a sensor coupling 773 may be included for coupling of a
pressure sensor to a gas channel of the module. In such a case the
coupling may be connected with a pressure sensor attached to the
electronics board 914 and the coupling permits the pressure sensor to
seal with the gas channel for sensing pressure in the gas channel. The
housing support 810 is also formed so as to include the gas channel GC.
The gas couplings (e.g., input coupling 112AM) may attach to the gas
channel GC of the housing support 810 such as by an interference fit or
may be formed as part of the housing support such as in the case of the
output coupling 110AM. Similarly, the electrical coupler 114 is attached
to the housing support 810 and wired to the electronics board 914 which
includes wiring for the bus. The electrical coupler may be either a male
plug or female receptacle version. In the version of FIG. 8A, a male plug
of the alarm module may be inserted into a female receptacle of the flow
generator module. Optionally, the alarm module may include an electrical
coupler of the female receptacle version (shown in FIG. 8B) on the
opposing side of the alarm module into which a male plug of the
humidifier module may be inserted.

[0103] A latching element 918 of the locking mechanism 116 including
latches 116L is attached to the housing support 810 with latch retainer
920 and retainer screws 924 so as to hold the latching element 918
against the housing support 810 but permit the latching element to
traverse laterally under the retainer for a latching movement. The latch
retainer 920 includes latch slots 921 in which the latches may move. The
lateral movement of the latching element, and particularly the latches
116L, permits the latches 116L to move to an engagement position EP and
disengagement position DP to engage or disengage with engagement
apertures or keepers 116K of another module structure (e.g., a flow
generator module) to which the alarm module may be attached.

[0104] A securing shaft 926 is provided for selectably securing and
releasing the latching element 918 to permit or prevent its lateral
movement under the retainer in a direction indicated by line AA of FIG.
9. As illustrated in more detail in FIGS. 10 and 10A, the securing shaft
926, which may for example include a screw head or bolt head, may include
multiple threaded portions, such as first threaded portion 1028 and
second threaded portion 1030 separated by a blank or unthreaded shaft
portion 1032. In an alternative form, securing shaft 926 may have a
single threaded portion. The threaded portions are sized for a threaded
aperture 1034 integrated with the latching element 918. When assembled,
the securing shaft 926 may be inserted within or through a housing
aperture 1036, which may be unthreaded, of the alarm module housing 106H
or housing support 810 to engage with the threaded aperture 1034 of the
latching element. A biasing element 1038, such as a spring, may be
provided to bias the latching element to a particular position along its
lateral movement path. For example, as discussed in more detail with
regard to FIG. 12, the biasing element may bias the latching element such
that the latches will automatically engage in a locked position when
inserted or engaged with the engagement apertures or keepers 116K of
another module. When a spring is implemented, the latching element 918
may include a spring mount 1049 for attaching the spring to the latching
element 918.

[0105] The components of the locking mechanism can provide a tamper
resistant means for releasably locking two modules together, such as the
alarms module and the flow generator module of a respiratory treatment
apparatus. The tamper resistant operation of the locking mechanism may be
considered in reference to FIGS. 11 through 14. In FIG. 11, the second
threaded portion 1030 is engaged with the threaded aperture 1034 of the
latching element 918 so as to secure the latching element from movement
such as by retaining it against a portion of the housing support 810. In
this position, the latching element 918 is locked from movement as the
shaft end 1102 of the securing shaft 926 plies against a shaft stop 1104
of the housing support 810 to force the latching element 918 against the
housing support 810 when the securing shaft is threaded into the latching
element 918. Thus, the latches 116L of the latching element will remain
engaged with the keepers 116K or engagement apertures of another module
in which they have been inserted and prevent the module from being
separated. Optionally, the housing support 810 may include a raised
aperture ridge 1140 surrounding the housing aperture 1036. The aperture
ridge 1140 may conceal the head of the securing shaft 926 below the ridge
when the securing shaft locks the latching element. In such a case, an
optional security label 1150 or sticker may be applied or adhered to the
housing support over the aperture ridge 1140 and the securing shaft 926
that is positioned beneath the ridge. Tampering with or removal of the
label 1150 may serve as an indication of unauthorized access to the
securing shaft 926 and unauthorized separation of the modules locked by
the locking mechanism.

[0106] In FIG. 12, the locking mechanism remains locked due to the bias of
the biasing element 1038 (not shown in FIG. 12) which may provide a
biasing force BF to bias the latching element 918 against the housing
support 810 even when the securing shaft has been unthreaded from the
threaded aperture 1034 of the latching element 918. In this biased
position, the latches 116L are still in the engaged position EP with
respect to any engagement aperture or keeper 116K of another module. Due
to the structure of the alarm module housing 106H, when the module is
attached to another module, the latching element or latches are not
readily accessible to move the latching element 918 into its
disengagement position DP.

[0107] In this regard, the alarm module housing 106H protects against or
conceals access to the latching element 918 and may provide only limited
access to it. For example, a small release port 1330, such as a pin hole
that may be covered by the label 1150, may be provided to access and move
the latching element 918 when it is unthreaded from the securing shaft as
illustrated in FIG. 13. The latching element overlaps the release port
1330 such as at an optional tail portion 1332 of the latching element
918. When applying a rigid wire or pin 1344 sized to pass through the
release port 1330, the wire or pin can ply against the latching element,
such as at the tail portion 1332, to counteract the biasing force and
laterally move the latching element to its disengagement position DP.
This lateral movement is permitted because the unthreaded shaft portion
1032 does not restrict lateral movement of the latching element. In other
words, the threaded aperture 1034 of the latching element 918 can
traverse along the unthreaded shaft portion 1032, and may do so without
rotation of the shaft portion due to the smaller diameter of the
unthreaded shaft portion relative to the first and second threaded
portions and the threaded aperture 1034, in order to move between the
engaged position and the disengaged position. Due to the biasing force
provided by the biasing element 1038 of the latching element 918, when
the pin or wire is removed, the latching element 918 will return to its
engaged position.

[0108] As shown in FIG. 14, the particular location of the shaft stop 1102
and size of the threaded portions and securing shaft 926, allows the
securing shaft to be tightened into the threads of the threaded aperture
of the latching element when the securing shaft is pressed inwards toward
the latching element 918 because the biasing force of the biasing element
pushes the latching element against the second threaded portion 1030.
However, it does not allow a pressing against the securing shaft 926 to
move the latching element 918 into its disengaged position from its
engaged position even when the securing shaft 926 is unthreaded from the
latching element 918. In this regard, the distance which the securing
shaft 926 may be pressed inward toward the shaft stop 1102 is not
sufficient for the end of the second threaded portion 1030 to push the
latching element to its disengaged position DP.

[0109] In the foregoing description and in the accompanying drawings,
specific terminology, equations and drawing symbols are set forth to
provide a thorough understanding of the present technology. In some
instances, the terminology and symbols may imply specific details that
are not required to practice the technology. For example, although the
terms "first" and "second" have been used, unless otherwise specified,
they are not intended to indicate any order but may be utilized to
distinguish between distinct elements. Moreover, although the technology
herein has been described with reference to particular embodiments, it is
to be understood that these embodiments are merely illustrative of the
principles and applications of the technology. It is therefore to be
understood that numerous modifications may be made to the illustrative
embodiments and that other arrangements may be devised without departing
from the spirit and scope of the technology. For example, as previously
discussed, in some embodiments the components within the housing of the
alarm module may include a controller with a processor to control alarms
with alarm components (e.g., speaker, lights, LEDs, LCD etc.) that
produce warning and alarms in the alarm module. However, in some
embodiments, such a controller or processor may be in other modules, such
as the flow generator module. In such a case, the alarm module need not
include a controller but may include the alarm components that
electronically couple to a controller of another module.

[0110] Moreover, while the illustrated alarms module includes a housing
that serves as an external casing to retain the components of the module,
in some embodiments the alarm components of the module may be configured
as an alarms card that may be inserted within another module, such as
inside the housing of the flow generator module. In such a case, the
alarms card may include the aforementioned components and functions of
the alarms module. However, the card may be docked with electrical and
gas connections on a mother board within the housing of the flow
generator, such as if the housing of the flow generator is configured to
open and close. In such a case, the housing of the flow generator module
can serve as an external casing for the alarms card as well as the flow
generator. Such an alarms card may or may not have an independent housing
of its own.

[0111] Still further, and as contemplated and previously described herein,
the modules may be coupled together with certain tamper resistant locking
features as described in more detail herein. Thus, modules of any
functionality may be coupled together with such features. For example, in
addition to being integrated with an alarms module or a flow generator
module, the tamper resistant locking features may be implemented with one
or more modules such as a wired and/or wireless communications module
that permits electronic data and instructions to be transferred to and
from the system or flow generator such as via network communications. For
example, a person may "daisy chain" one or more additional modules to a
respiratory treatment apparatus. Other module examples include a docking
interface module, such as one that permits easy electronic docking of
other user devices to the respiratory system so that they may operate and
communicate with the system (e.g., a music player dock, a LCD display
dock, a smart phone dock, an electronic personal data assistant dock
etc.).

[0112] In an alternative configuration, the one or more modules may be
connected to the top, bottom, front or back of the respiratory treatment
apparatus, or any combination thereof. In an alternative configuration,
the one or more modules may be connected to an interior portion of the
respiratory treatment apparatus.

[0113] One of the advantages of one form of the present technology, where
there are separate therapy and mitigation modules, is a reduced product
development time. Another advantage of one form of the present
technology, where there are separate therapy and mitigation modules, is
improved manufacturing efficiencies.

[0114] Despite the complexity of a speaker when compared to a buzzer, and
the more complicated manufacture procedure for including a speaker,
implementation of a speaker is preferred in the present technology. An
advantage of the use of a speaker in accordance with the present
technology is the improved electrical efficiency, which can lead to
reduced power requirements and reduced physical size of a corresponding
supercapacitor.

[0115] A further advantage of one form of the present technology is that
it improves the safety of a respiratory apparatus by making it difficult
for a patient to inadvertently remove a safety feature, e.g. an alarm
module, in those situations where it may be important for such an
additional module to remain connected once it has been added to the
respiratory treatment apparatus.